Incandescing electric lamp



(No Model.)

L. STIERINGER.

INGANDESGING ELECTRIC LAMP. No. 341,778. Patented May 11, 1886.

WEST W Y M, PETERS, Phnln-Lim a ndnr. wum lm, D c.

UNITED STATES PATENT ()FFICE.

LUTHER STIERINGER, OF NElV YORK, N. Y., ASSIGNOR TO THE EDISON LAMPCOMPANY, OF HARRISON, NEXV JERSEY.

lNCANDESClNG ELECTRIC LAMP.

SPECIFICATION forming part of Letters Patent No. 341,778, dated May 11,1886.

Application filed January 13, 1886.

To all whom it may concern:

Be it known that I, LUTHER STIERINGER, of New York city, in the countyand State of New York, have invented a certain new and usefulImprovement in Incandescing Electric Lamps, of which the following is aspecification.

Heretofore when incandescing electriclamps have been used in series withcurrents of high electro-motive force, with an electro-magi'ieticcut-out device for closing a shunt around each lamp, when its carbonfilament breaks difiiculty has arisen in the following way: If a breakoccurs in the filament, the current is apt to pass from the broken sideof the filament below the point of fracture across the vacuous space tothe other side, forming an are which follows down the carbomconsumingthe same, and down the leading-in wires to the glass, which beingintensely heated becomes a conductor of electricity, so that the currentcontinues to pass through the glass from one wire to the other and soproceeds down to the lampsocket and cut-out mechanism so that theseparts may be destroyed and the continuity of the series-circuit isfinally broken. The passage across the carbon being provided for thecurrent as soon as the carbon breaks the cutout mechanism 01" coursedoes not act.

My invention relates to means for overconr ing this difficulty bybreaking the are before it leaves the lamp, so that the electromagneticcut-out will then act to shunt the lamp. I accomplish this by fillingthe stem or tube through which the leadingin wires pass out side of theexhausted globe with a refractory insulating material which is notinjuriously affected by the heat of the are or current and prevents theare from passing from the wire to the glass, or from one wire to theother. The substance which I have found best to employ for the purposeis asbestus fiber, with which I fill the stem or tube. I have, however,tried numerous other substances with good results. Among these I maymention magnesium calcite, powdered soapstone, and terra-alba. Thesesubstances are efi'ective in operation, but the asbestus fiber is easierto handle and does not shift its position like the other materials,which are in-the form of powder. Any refractory insulating material notSerial X0. 188,446. (No model.)

broken in the stem of the lamp the cut-out v mechanism acts also in thesame way.

Dly invention is illustrated in the annexed drawings, in which Figure 1is a diagram of a portion of asystem ofelectric lighting embodying myinvention; Fig. 2, a view in elevation of one of the lamps, and Fig. 3 asection of the stem of the lamp after the are has been formed andbroken.

Like letters refer to corresponding parts in all these figures.

A is the exhausted inclosing-globe of an Edison electric lamp.

3 is the inner tube or stem. through which the leading-in wires c apass, being sealed in the glass of said tube where they pass through itat Z).

G is the carbon filament, attached to said wires at cc, preferably byelectroplated joint. \Vhen the are forms across the filament, it usuallypasses from the broken side thereof immediate] ybelow the fracture tothe opposite clamps. Both sides of the filament are consumed at once andthe wires usually are then consumed down to the glass, or nearly there.The current then passes across through the glass and usually consumesonly one wire, a, as seen in Fig. Continuing on through the wires andglass the current continues to prevent the operation of the cutout, andfinally reaches and destroys the socket and cut-out mechanism. Ihowever,as explained, fill the stem I3 with asbestus fiber D or other suitablematerial. The stopper E,inserted in the lower end of the stem, holds theasbestus in it and also keeps the wires apart. At first, as seen in Fig.3, the wire continues to be consumed for a certain distance down intothe asbestus that is, until the distance becomes so great that thecurrent or are cannot pass from the end of the wire to the glass at b.As soon as this point is reached, itis evident that the arc must ceaseat once since the asbestus prevents it from reaching the other wiredirect or from reaching the side of the tube.

In Fig. 1 is shown a cut-out devicewhich may be employed.

The lamps A A are in series in line L L in any suitable number. In ashunt, cl d, around each lamp is an electro-magnet, F, whosespring-retracted armature-lever G controls at e another shunt, f f. Ifcircuit through the lamp is interrupted in either of the two ways abovedescribed, the magnet F attracts its armature and closes shunt ff aroundthe lamp. A catch,g, is provided whichholds the shunt closed until thebroken lamp is replaced by a new one, when the catch is withdrawn byhand and the shunt is opened again.

I am aware of United States Patent to Perkins, No. 287,3l4, datedOctober 23, 1883, in which is described the use of mineral wool placedin the stem of a lamp to prevent the conduction of heat down to thesocket. Mineral wool is, however, nota material which is refractoryunder the heat of the are, and will not act to break the arc inthemanner above set forth.

having its leading-in wires within the glass stem separated from eachother and from the glass by asbestus fiber or equivalent refractoryinsulating material, of electromagnetic cut-out mechanism for each lamp,substantially as set forth.

This specification signed and witnessed this 4th day of January, 1886.

LUTHER STIERINGER.

Witnesses:

A. W. KIDDLE, E. O; ROWLAND.

